Spring-nut applying tools



July 3, 1956 D. F. GARMAN 2,752,805

SPRING-NUT APPLYING TOOLS Filed July 6, 1954 2 Sheets-Sheet 1 v INVENTOR Dan/.440 f? Gm wma/ ATTORNEY Z,752,ll5 SP G-NIUT APllLl! 1N G TOULS Donald F. Garman, Cleveland, (lihio, assignor to Tinnergran Products, inn, Cleveiand, Ohio, a corporation of Application luly 6, 1954, Serial No. 441,389 6 (Jlaiins. (Cl. 81--3) This invention deals with an improved tool for applying a sheet metal spring nut to secured position on a stud, and an improved construction for a sheet metal spring nut which is adapted to be assembled on the tool and easily and quickly applied by the tool to secured position on the stud in a single expeditious operation.

The arrangement is such that the improved tool of the invention provides for the application of a spring nut to secured position on a stud with relatively greater speed and facility than heretofore known tools of this character, while otherwise securing the spring nut by a pushing action directly on the spring nut without need for bolstering the head of the stud or the part to which it is connected. This is highly advantageous in instances wherein the stud is connected to or extends from a relatively fra ile plastic or glass part, for example, such that it is necessary for the spring nut to be applied to the stud without any axial pull or distortion thereon which would break the stud or fracture the relatively fragile glass or plastic part to which the stud is connected.

Another example of the highly practical and advantageous use of the invention resides in the preparation of sand cores for casting wherein the sand cores are held together by elongate rods and spring nuts secured on the ends of the rods which must necessarily be applied solely by a pushing action on the spring nuts without pulling on or disturbing the rods in any way in which the sand cores would be deformed or damaged by unintended movement of the rods therein.

The improved spring nuts of the invention and the tool for applying the same are adapted for a wide range and variety of applications and uses but are particularly advantageous in what are known as blind fastening assemblies wherein both sides of the parts secured are not conveniently or readily accessible and the final fastening of the parts is more advantageously or necessarily performed by an operation taking place entirely from the accessible side of the assembly.

With objects apparent from the foregoing in view, further objects and advantages, and other new and useful features in the construction, arrangement and general combination of parts of the invention will be apparent as the followin description proceeds with reference to the accompanying drawin s, for purposes of illustration but not of limitation, in which like reference characters designate like parts throughout, and in which:

Fig. 1 is a vertical sectional view of a tool in accord ance with the invention, and shows a spring nut assembled on guide fingers on the forward end of the tool in position to be applied to secured position over the end of a projecting stud of an assembly to be secured;

Fig. 2 is a view along line 2-2 of Fig. 1 looking in the direction of the arrows, and shows the spring nut in bottom plan on an enlarged scale as assembled on the guide fingers on the forward end of the tool;

Fig. 3 is a perspective view of the spring nut as seen from the upper surface thereof, and shows the special construction of the spring nut for fitting the same in assembled relation on the forward end of the tool, shown in broken lines;

Fig. 4 is a similar perspective view of the spring nut showing the same as applied by the tool to secured position over the end of the projecting stud;

stem Fig. 5 is a sectional view showing the spring nut in edge elevation as applied to secured position on the stud with the respective elements of the tool represented in broken lines in the position of engagement with the spring nut and the projecting stud on which the spring nut is secured;

Fig. 6 is an enlarged sectional view showing the elements of the forward end of the tool with a spring nut assembled thereon and fitted over the end of the projecting stud in the initial step of applying the spring nut to secured position on the stud;

Fig. 7 is a sectional view similar to Fig. 6 showing the elements of the forward end of the tool as actuated to project the spring nut to secured position on the projecting stud; and,

Fig. 8 is a sectional view similar to Fig. 7 showing the guide fingers of the tool in a modified form for applying spring nut to secured position on a stud having a ringharbed, serrated or similarly shouldered formation in either a headed type of fastener, as shown, or in the manner of a stud connected to a part to be secured.

Referring now, more particularly, to the drawings, there is shown in Fig. 4 a fastening arrangement in which a part A is secured to an associated part by a spring nut 10 in accordance with the invention applied to connecting means in any of the forms of a separate or integral plain stud, barbed shank, rivet, nail or threaded fastener, or the like. In the present illustration, for eX- ample only, the part A represents a sand core held together by elongate rods having free ends 1, whichdefine projecting studs 1 to which the spring nuts 10 are secured solely by a pushing action on the spring nuts without moving or disturbing the rods in any way in which the sand core would be mutilated or deformed by unintended movement of the rods therein. In a related type of fastening assembly, the part A may he a relatively fragile plastic or glass part formed with one or more integrally molded studs l or equivalent studs provided in the manner of inserts embedded therein in the molding operation, or with said studs extending through aligned openings in two or more parts to be secured with the free ends of the studs projecting beyond. the assembled parts in position for the application of spring nuts 10 thereto for securing said parts in a completed installation.

it will be understood, further, that in many assemblies of this character, the head portions of the studs or the areas to which the studs are connected are not usually accessible for bolstering the same during the application and tightening of the spring nuts thereon and accordingly, it is necessary or desirable to apply the spring nuts by an operation taking place entirely from the accessible side of the assembly. in this relation, the improved tool of the invention, Fig. 1, is particularly advantageous in applying and tensioning a spring nut 10 entirely from the accessible side of an assembly without requiring the associated stud 1 to be bolstered from the opposite side of the assembly, as is necessary in the application of a spring nut by a thrust-type tool, for example, in which there is considerable danger of mutilation, cracking or breakage of such relatively fragile parts in this respect also.

The spring nut devices iii are essentially sheet metal locking plates or clips which are constructed from relatively thin sections of any suitable sheet metal, preferably spring metal such as spring steel or cold rolled metal having spring-like characteristics. The spring nut 10 may be provided from blanks of various outlines but, as shown in Fig. 2, is most economically constructed from a simple generally rectangular section which may be provided at very low cost from ordinary strip stock with little loss or waste of material. The blank preferably is provided with rounded corners and is bent into the form of a generally bowed or arched body or base between end sections 12 which are of sufiicient length to define substantial bearing surfaces or spring clamping elements capable of frictional sliding relation on the sur face of the adjacent part A or other work secured thereby upon tensioning of the spring nut in fully applied fastening position.

At the substantial center or apex of the bowed or arched body or base of the spring nut, a stud receiving opening is provided together With a pair of spaced parallel elongate cutouts in the form of slots or slits 14 extending lengthwise on opposite sides of said stud receiving opening. The slots 14 include special laterally enlarged areas 15 on the sides thereof and are so provided in the blank as to define a pair of cooperating substantial tongues 17 or the like, between bowed or arched side or bridge sections 18, extending lengthwise adjacent said tongues 17 and defining said resilient bowed or arched body or base of the spring nut 10.

In the completed spring nut 10, special recesses or holes are formed by the laterally enlarged areas 15 of the slots 14 and the adjoining space of said slots 14 adjacent the sides of the tongues 17. These special holes or recesses 15 provide for assembly of the spring nut 10 on the tool, Fig. 1, preparatory to the application and securing of the spring nut 10 on an associated stud 1, as hereinafter set forth. The extremities of said tongues 17 are at least equal to or slightly greater in width than the root diameter of the stud 1 and are preferably V-notched and oppositely disposed to cut into embedded relation with the stud in substantially equal biting engagement therewith in applied fastening position. The tongues 17, otherwise, have the corners thereof cutaway, preferably in a bevelled formation, as shown, to provide the extremities of said tongues 17 in a predetermined spacing suitable for clearing elements of the tool adapted to pass between said tongues 17 in the application and tightening of the spring nut 10 to fastening position on the stud 1, as presently to be described.

Said tongues 17 preferably are relatively short and bent into substantially ogee formation to extend within or slightly outwardly out of the contour of the generally bowed or arched body of the spring nut 1 at the crown or apex thereof. The tongues 17, thus provided, are possessed of unusual inherent strength and sufficient resiliency to yield as necessary for the extremities thereof to admit therebetween a suitable stud 1 in any form of a separate or integral plain stud, barbed shank, rivet, nail or threaded fastener, or the like.

The arrangement, otherwise, is such that the bowed or arched body of the spring nut 10 provides a resilient spring locking plate which is somewhat more flexible than the usual spring nut. The tongues 17 are yieldable with respect to said bowed or arched body and relatively to each other in such a way that the V-shaped extremities of said tongues 17 are readily adapted for sliding along the smooth shank of a plain stud 1 or for snapping over the ribs of a ring-barbed stud in one direction in the manner of yieldable pawls sliding over a ratchet in what may be termed, a one-way clutch gripping action with the stud. The spring nut device 10, accordingly, may be speedily applied by the tool of the invention to secured position on a stud 1 by a substantially axial pushing force in a minimum of time and effort, and the bowed or arched body simultaneously depressed toward fiat, as seen in Fig. 5, to tightly secure the same against the adjacent work A under a tensioned spring locking action.

It has been found that this most effective locking action of a spring nut 10 to provide a tight, rigid installation is best obtained when the generally arched or bowed. body of the spring nut defined by the side sections 18, is depressed without any substantial pressure being exerted directly on the tongues 17; any substantial pressure on saidv tongues 17 prevents the spring nut from having easy slid ing movement axially of a plain stud 1 or over the ribs of a barbed stud on being applied and often bends the tongues such that the extremities thereof are deformed out of position for most effective contact with the stud and thus have a tendency to slip and permit the spring nut to loosen from tensioned, finally applied position in a completed assembly.

The tensioning of the spring nut 10 may be performed in any suitable way for depressing the same, as aforesaid, but preferably by the use of a special tool comprising a pressure head designed to engage the arched or bowed side or bridge sections 18 and the end sections 12 without exerting pressure directly on said tongues 17. Thus, pressure may be applied to the generally arched or bowed body of the spring nut 10 to depress and tension the same without likelihood of deforming the tongues 17; and accordingly, when the tool is withdrawn and the attendant pressure removed from the depressed body of the spring nut, the spring nut attempts to assume its initial, untensioned bowed or arched formation such that the extremities of the tongues 17 are urged inwardly under spring tension into locked biting engagement with the stud 1 in the fully applied position of the spring nut. The spring nut 10 is thereby secured to the stud 1 under a spring locking action wherein the tongues 17, in locked biting engagement with the stud, exert a downward force on the body of the spring nut, in conjunction with the upward reaction spring force applied to said tongues 17 by the depressed and tensioned body of the spring nut in attempting to assume its initial bowed or arched configuration.

Fig. 1 shows a tool T for applying and tensioning a spring nut 19 in secured position on a stud 1 by an operation taking place entirely from the accessible side of the assembly as is required in installations, such as previously described, in which it is impractical or inconvenient to bolster the stud during the depressing action for tensioning the spring nut 10 in applied position on the stud. The tool is shown provided as a hand manipulated push-pull implement comprising relatively simple actuating elements which may be readily embodied in any similar tool operated by a suitable electrical motor or hydraulic or air pressure means, as desired. The body of the tool T comprises a tubular barrel 20 provided with a ball shaped hand grip or handle 21 and an axial bore having a closed inner wall 22 and a generally circular outer end 24 defining a peripheral tool head adapted for applying the predetermined size of spring nut for which the tool is intended for use. The barrel 20 is provided with a pair of aligned elongate openings 26 defining slideways intermediately thereof and the ends of these slideways 26 define forward abutments or stops 27 and rearward abutments or stops 23.

A plunger 30, or the like, is slidably received in the tubular barrel 20 and is provided with a passage for connecting thereto a screw 32 extending through the aligned slideways 26 in the brrel 20. Preferably a sleeve 34 is slidably telescoped over the barrel 20 and is provided with holes aligned with said slideways 26 and through which said screw 32 extends and secures a pair of short oppositely extending rods 35, 36, to said plunger 30 and said slidable sleeve 34. The rods 35, 36, define grips or trigger elements for controlling movement of the plunger 30, and Whileeither one of said rods would be adequate for this purpose, a preferred construction involves the use of both rods 35, 36, in an arrangement in which the rod 35 is recessed to seat the head of the screw 32 for securing the same while the other rod 3-6 is secured on the threaded end of said screw 32.

A coil spring 38 is retained in the barrel 20 against the closed end wall 22 of the bore therein and bearing on the adjacent inner end of the plunger 30 to urge the same to its normal forwardly projected position relatively to the barrel 20 as limited by the screw 32 in engagement with the abutments or stops 27 defined by the forward ends of the slideways 26 in said barrel 20. The plunger 30 is thus retained in the barrel 2b in its normal position in which the tool is ready for use. The slots 26 in the barrel 20 are of a length approximating the necessary amount of forward travel of the barrel 2t) relatively to the plunger 30 when actuated by pressure on the ball-shaped handle 21, with such forward travel of the barrel 20 terminating when the rearward steps or abutments 28 defined by the rear ends of said slideways 26 come into engagement with the screw 32 connected to said plunger 30.

The plunger 3t? is provided on its forward end with a pair of elongate resilient arms 40 having guide fingers 41 in substantial alignment with said arms. 40 and projecting a predetermined distance beyond the tool head 24 in the normal position of the tool as shown in Figs. 1 and 6. As best seen in Fig. 6, the guide fingers 41 are so formed that the outer sides thereof define outwardly inclined cam surfaces 42 tapering gradually outwardly from each other. On the inner sides of said guide fingers 41, there are provided a pair of opposite integral stud gripping jaws 44 having curved faces, as seen in Fig. 2, corresponding substantially to the outer contour of the stud 1 of the assembly of parts to be secured. The arrangement, otherwise, is such that the guide fingers 41 have cross-sections in the form of chords corresponding to and slightly smaller than the contour of the special tool receiving recesses 15 in the spring nut ill so as to be readily received in said recesses 15, as shown in Fig. 2, with the gripping jaws 44 adapted to pass freely between the extremities of the tongues 1'7v Thus, the spring nut it is easily and quickly assembled onto said guide fingers 41 as shown in Figs. 1, 2 and 6, preparatory to the application and securing of the spring nut on the associated stud 1, as shown in Figs. 4 and 5.

Preferably, the plunger 30 is provided with a removable gauge pin 46 which has its inner end removably retained in an aperture 47 between the spring arms 40 with the outer end of said pin 46 extending to a predetermined point between the guide fingers 41 in position to engage the end of the stud l. The gauge pin 46 is thereby adapted to locate the jaws 44 on said guide fingers 41 for gripping the stud l at substantially the predetermined point in which the spring nut it may be applied onto said stud 1 by the tool head 24 to the precise and most effective position intended.

With the spring nut 1t} and tool T provided substantially as described, the application of a spring nut 10 to secured position on its associated stud 1 is readily effected by first assembling the spring nut 10 onto the projecting guide fingers 41 of the tool as shown in Figs. 1 and 2. The guide fingers 41 readily slip through the tool receiving recesses in the spring nut lltl and the gripping jaws 44 pass easily between the extremities of the tongues 17 of the spring nut to a position in which the circular tool head 24 bears against the convex surface of the spring nut 10 as illustrated in Figs. 1 and 6.

The tool T with the spring nut 10 assembled on the guide fingers 41 is then fitted over the projecting end of the stud l, as shown in Fig. 6 to the precise location determined by the gauge pin 46 engaging the end of stud 1. The gripping jaws 44- on the plunger 30 are thus located at the predetermined position for gripping said stud 1 and for the subsequent projection or pushing of the spring nut El onto said stud l by the tool head 24, but only to the extent of the predetermined forward movement of the tool head 24 relatively to the plunger 39 as limited by the rearward stops or abutments 28 on the barrel when moved into contact with the screw 32 connected to said plunger 3%.

The action is such that the gripping jaws 4 close upon and rigidly grip the stud 1 while the cooperating tool head 24 moves forwardly relatively thereto to depress and flatten the bowed or arched side sections 18 of the spring nut 10 against the adjacent face of the work A substantially as shown in Figs. 5 and 7. Said peripheral tool head 24 is so designed as to engage, in any position of application,

the bowed or arched side sections 18 and the end sections 12 adjacent the bases of the projecting tongues 17 such that no pressure is exerted on said tongues 17 which would tend to mutilate or distort the same out of their normal formation adapted for most efiective fastening engagement with the stud 1. Said tongues 17, otherwise, are receivable in the bore of the tool head 24 and are thereby free to yield and flex as necessary upon actuation of the tool head 24 to such position of most effective fastening engagement with the stud 1.

Accordingly, with the spring nut assembled on the guide fingers 4i and the gripping jaws 44 thereon fitted over the end of the stud 1 as shown in Fig. 6, the operator initially actuates the tool by holding steady one or both of the grips or trigger elements 35, 36, while pressing upon the ballshaped handle 21 to move the barrel 2i) and the tool head thereon in a forward direction over said guide fingers 41. As the barrel 20 is moved forwardly, the coil spring 38 is compressed against the end of the plunger 36, and the tool head 24 on the end of the barrel 20 engages the outwardly inclined cam surfaces 42 on the guide fingers 41 to provide a gradual compression of said guide fingers 41 which causes the gripping jaws 44 thereon to move inwardly into fixed gripping engagement with the stud 1. At the same time, the tool head 24 pushes the spring nut lid over guide fingers 41 to a position in which the tongues 17 snap over the end of the stud 1 and spring into biting contact with the stud 1, following which the spring nut 13 is pushed completely olf of the ends of the guide fingers 41 and onto the stud 1. The spring nut 10 readily slips over and off of the guide fingers 41 in this manner inasmuch as the tool receiving recesses 15 therein are loosely fitted about said guide fingers 41 while the extremities of the tongues 17 have sufficient clearance from the jaws 44 for this purpose, as aforesaid.

During this forward movement of the tool head 24 over the guide fingers 41, the gripping jaws 44 remain in fixed gripping engagement with the stud 1 as the spring nut 10 is pushed axially of the stud to a position in which the end sections 12 of the spring nut 10 engage the adjacent surface of the part A, whereupon the tool head 24 bears upon the bowed or arched side sections 18 as shown in Fig. 7 to substantially flatten the same, thereby tensioning the body of the spring nut and causing the tongues 17 to seat in biting locked engagement with the stud 1 as illustrated in Figs. 4 and 5.

it will be appreciated that in the final application and tightening of the spring nut ltl on the stud 1, the jaws 44 on the guide fingers 41 remain in fixed gripping engagement with said stud 1 as the tool head 24 moves forwardly relatively thereto to depress and substantially flatten the spring nut lit in final position. Thus, the stud 1 on the end of a rod in a sand core, A, for example, is not moved or otherwise disturbed in any way in which the sand core would be deformed or damaged by unintended move ment of the rod therein. Likewise, in the event that the part A a relatively fragile plastic or glass part with the studs 1 integrally molded thereon, there is little pull or distortion on the studs which might cause cracking or breaking of the studs.

When the ball-shaped handle 21 of the tool is released, the compressed coil spring 33 is free to expand and accordingly, urges the barrel 2t) rearwardly to its initial, normal position shown in Fig. l. The cam surfaces 42 of the guide fingers 41 thus clear the tool head 24 such that said guide fingers 41 are free to spring outwardly sufficiently for the jaws 44 carried thereby to disengage from the stud l, whereupon the tool may be easily and quickly withdrawn.

When the tool is withdrawn and the attendant pressure removed from the depressed body of the spring nut 10, the spring nut naturally tends to assume its initial arched or bowed configuration, thereby forcing the V-shaped extremities of the tongues 17 inwardly toward each other to cut into and become embedded in the stud in permanently locked relation therewith, as aforesaid. Preferably the body of the spring nut 10 is designed to assume a slightly bowed or arched formation in its fully applied position, as seen in Fig. 5, to retain the tongues 17 in such locked engagement in the stud 1 under continuously effective spring tension in a manner whereby the spring nut 10 is not subject to loosening or removal under the most severe conditions of shock, vibration, or the like.

Fig. 8 shows the tool of the invention as provided for applying a spring nut 10 to secured position on a headed fastener 5, for example, having a serrated or ring-barbed stud composed of a series of transverse abutments or shoulders 6 on said stud. Such a headed fastener is advantageously driven into two or more parts B, C, to be secured, and may otherwise have a smooth, plain stud in the manner of a nail, rivet or the like, suitable for the application of a spring nut 10 over the projecting end of the stud to retain said parts B, C, in secured position. in the present example, the headed fastener 5 having a ringbarbed stud 6 is advantageous in many assemblies wherein one or both of the parts B, C, may be made of fibre board, plywood, insulating material, or the like, having a relatively soft and porous composition. A ring-barbed stud is such as to define a series of sharp transverse abutments or shoulders 6 spaced by grooves receiving the adjacent surrounding material of the parts B, C, on being driven therein, to interlock with the stud and engage particularly said shoulders 6 thereof and thereby resist withdrawal of the stud after being thus initially applied by being driven into said parts B, C. Thus, headed fasteners 5 having a serrated or ring-barbed stud 6 provide sufficient holding ability in such relatively soft and porous material for temporarily holding the same in properly assembled relation, whereas an ordinary nail having only a smooth or roughened shank would not be suitable for this purpose. The ring-barbed shank 6 also defines a pronounced shoulder or rib construction engageable by the tongues 17 of the spring nut to provide a positively locked fastening of the parts of the assembly in permanently secured relation.

The tool of the invention, as provided for applying a spring nut 10 to secured position on such a ring-barbed stud 6, Fig. 8, is substantially the same as that previously described except that the stud gripping jaws on the guide fingers 41 are provided as inturned claws 54 having a V-shaped formation corresponding substantially to the V-shaped grooves between the ribs or shoulders 6 on the ring-barbed sfud so as to fit readily therein as shown in Fig. 8.

In the application of a spring nut 10 to secured position on such a ring-barbed stud 6, the spring nut 10 is, likewise, first assembled on the guide fingers 41, and said guide fingers 41 fitted over the projecting end of the stud with the V-shaped jaws 513 received in a selected groove between the transverse ribs or shoulders 6 on said stud. The gauge pin 46 shown employed in Figs, 1, 6 and 7 may be omitted, if desired, inasmuch as a satisfactory operation is obtained with the jaws 50 in engagement with the stud 6 at any of several points along the length thereof so long as the travel of the tool head 24 is sufiicient to advance the spring nut 10 on the ring-barbed stud 6 to fully applied position against the surface of the adjacent part C or other work secured thereby.

The tool is then actuated to operate in the manner described with reference to Figs. 1, 6 and 7 to project the spring nut 10 over and off of the guide fingers d1 into fully applied position on the ring-barbed stud 6, as shown in Fig. 8, in a manner whereby the bowed or arched body of the spring nut 10 is substantially flattened and the extremities of the tongues 17 of the spring nut engage the rib or shoulder 6 on the stud immediately adjacent thereto. When the tool is withdrawn, the spring nut 10, likewise, tends to assume its initial bowed or arched configuration to cause the notched extremities of said tongues 17 to cut into and become embedded in the root diameter of the stud and in positive abutting relation with the engaged shoulder or rib 6 in permanently locked position on the stud, as aforesaid. In this instance also, thespring nut is preferably in a slightly bowed or arched condition in fully applied position such that the tongues 17 are retained in such locked engagement with the ring-barbed stud 6 under continuously effective spring tension.

In applications where it is desired that the parts B, C, of the assembly, Fig. 8, be secured in tightly clamped relation, the operation of the tool is altered to provide a pull on the grips or trigger elements 35, 36, simultaneously with a push on the ball-shaped handle 21. This provides for an axial pull on the jaws 50 on the guide fingers 41 which is transmitted to the stud 6 as the spring nut 10 is pushed thereon in a manner whereby the secured parts B, C, are clamped tightly between the head 5 of the stud and the fully applied and flattened spring nut 10; and accordingly, when the tool is withdrawn and the flattened spring nut 10 attempts to assume its initial bowed or arched formation, the extremities of the tongues 17 not only are urged inwardly toward each other into embedded, positively locked, biting engagement with the stud 6, but said tongues 17 also exert an axial pull on said stud 6 to draw the parts B, C, of the assembly into tight, rigid and permanently secured relation under continuously effective spring tension.

The spring nut 10 preferably is constructed of relatively thin sheet metal the thickness of which is selected according to service requirements and the predetermined size of the parts to be secured thereby. The spring nut 10 is most effective when provided of spring metal suitably tempered and otherwise treated to give the desired toughness and hardness, particularly in the case of devices Which are intended for heavy duty applications. A cheap and highly satisfactory spring nut in accordance with the invention may be provided from cold rolled metal such as cold rolled steel which is untempered but of a spring metal nature and capable of providing an effective and reliable securing device as and for the purposes described. A divisional application Serial Number 507,851 filed May 12, 1955, is directed to the new and improved construction of the spring nut.

While the invention has been described in detail with specific examples of a preferred form of tool and spring nut, such examples are intended as illustrations only inasmuch as the invention fully contemplates various modifications in both the tool and the spring nut which may be provided without departing from the spirit and scope of the invention.

What is claimed is:

1. A tool for applying a sheet metal spring fastener to secured position on a stud, said fastener having a resilient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer end thereof, a plunger slidable in said tubular barrel carrying spring arms and guide fingers on the ends of said arms projecting normally beyond said tool head in substantial alignment with said arms, said guide fingers having a cross section corresponding substantially to the cross-sectional contour of said tool receiving holes and being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative movement of the barrel and plunger such that said guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener off said guide fingers into secured position on said stud.

2. A tool for applying a sheet metal spring fastener to secured position on a stud, said fastener having a resilient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer end thereof, a plunger slidable in said tubular barrel carrying spring arms and guide fingers on the ends of said arms projecting normally beyond said tool head, said guide fingers being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative movement of the barrel and plunger such that said guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener olf said guide fingers into secured position on said stud, and a gauge pin carried by said plunger between said guide fingers adapted to engage the end of said stud for locating said stud gripping jaws in predetermined position for gripping said stud preparatory to the application of the fastener to secured position on said stud.

3. A tool for applying a sheet metal spring fastener to secured position on a stud, said fastener having a re silient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer end thereof, a plunger slidable in said tubular barrel carrying spring arms and guide fingers on the ends of said arms having outwardly diverging cam surfaces, a compression spring in said barrel bearing on said plunger to maintain the same in normal position with said guide lingers projecting normally beyond said tool head, said guide fingers being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative movement of the barrel and plunger such that said outwardly diverging cam surfaces on the guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener off said guide fingers into secured position on said stud, and a gauge pin carried by said plunger between said guide fingers adapted to engage the end of said stud for locating said stud gripping jaws in prede termined position for gripping said stud preparatory to the application of the fastener to secured position on said stud.

4. A tool for applying a sheet metal spring fastener to secured position on a stud, saidfastener having a resilient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer end thereof and an intermediate elongate slot the ends of which define forward and rearward stops, at plunger slidable in said tubular barrel carrying spring arms and guide fingers on the ends of said arms, a compression spring in said barrel bearing on said plunger to maintain the same in normal position with said guide fingers projccting normally beyond said tool head, a handle member comprising a bolt, or the like, connected to said plunger and extending through said slot in said barrel in engagement with said forward stop in said normal position of the plunger, said guide lingers being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative movement of the barrel and plunger such that said guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener off said guide fingers into secured position on said stud, and a gauge pin carried by said plunger between said guide fingers adapted to engage the end of said stud for locating said stud gripping jaws in predetermined position for gripping said stud preparatory to the application of the fastener to secured position on said stud.

5. A tool for applying a sheet metal spring fastener to secured position on a stud, said fastener having a resilient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer, end thereof and an intermediate elongate slot the ends of which define forward and rearward stops, a plunger slidable in said tubular barrel carrying spring arms and guide fingers on the ends of said arms having outwardly diverging cam surfaces, a compression spring in said barrel bearing on said plunger to maintain the same in normal position with said guide fingers projecting normally beyond said tool head, a handle member comprising a bolt, or the like, connected to said plunger and extending through said slot in said barrel in engagement with said forward stop in said normal position of the plunger, said guide fingers being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative movement of the barrel and plunger such that said outwardly diverging cam surfaces on the guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener off said guide fingers into secured position on said stud, and a gauge pin carried by said plunger between said guide fingers adapted to engage the end of said stud for locating said stud gripping jaws in predetermined position for gripping said stud preparatory to the application of the fastener to secured position on said stud.

6. A tool for applying a sheet metal spring fastener to secured position on a stud, said fastener having a resilient body provided with stud engaging means and tool receiving holes in said fastener body, said tool comprising a tubular barrel having a tool head on the outer end thereof and opposite elongate slots in said barrel between the ends thereof, the ends of said slots defining pairs of forward and rearward stops, a plunger slidable in said tubular bar rel carrying spring arms and guide fingers on the ends of said arms having outwardly diverging earn surfaces, a compression spring in said barrel bearing on said plunger to maintain the samein normal position with said guide fingers projecting normally beyond said tool head, a handle member comprising a bolt, or the like, connected to said plunger and extending through said slots in said barrel in engagement with said pair of forward stops in said normal position of the plunger, said guide fingers being adapted to extend through said tool receiving holes in the fastener body to support the fastener on the tool preparatory to securing the fastener on said stud, said guide fingers including stud gripping jaws normally in released position and adapted to grip said stud upon relative move ment of the barrel and plunger such that said outwardly diverging cam surfaces on the guide fingers are engaged by said barrel to cause said jaws thereon to grip said stud as the tool head pushes the fastener off said guide fingers into secured position on said stud, said pair of rearward stops being adapted to engage said bolt, or the like, connected to the plunger to limit the relative movement of the barrel and plunger, and a gauge pin carried by said plunger between said guide fingers adapted to engage the end of said stud for locating said stud gripping jaws in predeternined position for gripping said stud preparatory to the application of the fastener to secured position on said stud.

References Cited in the file of this patent UNITED STATES PATENTS 2,341,063 Tinnerman Feb. 8, 1944 2,382,520 Tinnerman Aug. 14, 1945 2,498,324 Yourglich Feb. 21, 1950 2,568,584 Hartman Sept. 18, 1951 

